1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/mm.h> |
3 | #include <linux/kernel.h> |
4 | #include <linux/slab.h> |
5 | #include <linux/sched/signal.h> |
6 | #include <linux/sched/task_stack.h> |
7 | #include <linux/export.h> |
8 | #include <linux/stackprotector.h> |
9 | #include <asm/fpu.h> |
10 | #include <asm/ptrace.h> |
11 | |
12 | struct kmem_cache *task_xstate_cachep = NULL; |
13 | unsigned int xstate_size; |
14 | |
15 | #ifdef CONFIG_STACKPROTECTOR |
16 | unsigned long __stack_chk_guard __read_mostly; |
17 | EXPORT_SYMBOL(__stack_chk_guard); |
18 | #endif |
19 | |
20 | /* |
21 | * this gets called so that we can store lazy state into memory and copy the |
22 | * current task into the new thread. |
23 | */ |
24 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
25 | { |
26 | unlazy_fpu(src, task_pt_regs(src)); |
27 | *dst = *src; |
28 | |
29 | if (src->thread.xstate) { |
30 | dst->thread.xstate = kmem_cache_alloc(cachep: task_xstate_cachep, |
31 | GFP_KERNEL); |
32 | if (!dst->thread.xstate) |
33 | return -ENOMEM; |
34 | memcpy(dst->thread.xstate, src->thread.xstate, xstate_size); |
35 | } |
36 | |
37 | return 0; |
38 | } |
39 | |
40 | void free_thread_xstate(struct task_struct *tsk) |
41 | { |
42 | if (tsk->thread.xstate) { |
43 | kmem_cache_free(s: task_xstate_cachep, objp: tsk->thread.xstate); |
44 | tsk->thread.xstate = NULL; |
45 | } |
46 | } |
47 | |
48 | void arch_release_task_struct(struct task_struct *tsk) |
49 | { |
50 | free_thread_xstate(tsk); |
51 | } |
52 | |
53 | void arch_task_cache_init(void) |
54 | { |
55 | if (!xstate_size) |
56 | return; |
57 | |
58 | task_xstate_cachep = kmem_cache_create("task_xstate" , xstate_size, |
59 | __alignof__(union thread_xstate), |
60 | SLAB_PANIC, NULL); |
61 | } |
62 | |
63 | #ifdef CONFIG_SH_FPU_EMU |
64 | # define HAVE_SOFTFP 1 |
65 | #else |
66 | # define HAVE_SOFTFP 0 |
67 | #endif |
68 | |
69 | void init_thread_xstate(void) |
70 | { |
71 | if (boot_cpu_data.flags & CPU_HAS_FPU) |
72 | xstate_size = sizeof(struct sh_fpu_hard_struct); |
73 | else if (HAVE_SOFTFP) |
74 | xstate_size = sizeof(struct sh_fpu_soft_struct); |
75 | else |
76 | xstate_size = 0; |
77 | } |
78 | |